MUC16 and TP53 family co-regulate tumor-stromal heterogeneity in pancreatic adenocarcinoma.

MUC16/CA125 is one of the few oldest cancer biomarkers still used in current clinical practice. As mesothelium is an abundant source of MUC16 and a major contributor to stromal heterogeneity in PDAC, we investigated the regulation of MUC16 in tumor and stromal compartments individually. The trajectories constructed using the single-cell transcriptomes of stromal cells from KPC tumors demonstrated continuity in the trajectory path between MUC16-expressing mesothelial cells and other CAF subsets. Further, the tumor tissues of MUC16 whole-body knockout (KPCM) showed dysregulation in the markers of actomyosin assembly and fibroblast differentiation (iCAF and myCAF), indicating that MUC16 has an extra-tumoral role in controlling CAF differentiation. Although we found mesothelium-derivative stromal cells to be bystanders in normal pancreas, the proportion of these cells was higher in invasive PDAC, particularly in TP53 deficient tumors. Moreover, we also detail the regulation of MUC16, KRAS, and SOX9 by TP53 family members (TP53 and TP63) using multi-omics data from knockout models, PDAC cell lines, and human PDAC tissues.

A reliable, reproducible flow cytometry protocol for immune cell quantification in human adipose tissue.

The ability to accurately identify and quantify immune cell populations within adipose tissue is important in understanding the role of immune cells in metabolic disease risk. Flow cytometry is the gold standard method for immune cell quantification. However, quantification of immune cells from adipose tissue presents a number of challenges because of the complexities of working with an oily substance and the rapid deterioration of immune cell viability before analysis can be performed. Here we present a highly reproducible flow cytometry protocol for the quantification of immune cells in human adipose tissue, which overcomes these issues.

Sex Affects Regional Variations in Subcutaneous Adipose Tissue T Cells but not Macrophages in Adults with Obesity.

OBJECTIVE: The inflammatory environment in lower-body subcutaneous adipose tissue (SAT) has been largely unexplored. This study aimed to examine the effects of region (upper body vs. lower body) and sex on SAT immune cell profiles in young adults with obesity. METHODS: Abdominal (AB) and femoral (FEM) SAT was collected from 12 males (mean [SEM] age = 30.8 [1.4] years; mean [SEM] BMI = 34.1 [1.1] kg/m2 ) and 22 females (mean [SEM] age = 30.6 [0.6] years; mean [SEM] BMI = 34.0 [0.7] kg/m2 ) with obesity via needle aspiration. Flow cytometry was used to quantify macrophage (CD68+) and T-cell (CD3+) subpopulations in the stromovascular fraction of each SAT region. RESULTS: Females had a greater proportion of most T-cell types (CD3+CD4+CD45RA+, CD3+CD4+CD45RA-, and CD3+CD8+CD45RA+) in FEM compared with AB SAT, while males had similar proportions in both regions. Regardless of sex, the M1-like macrophage population (CD68+CD206-) was proportionally higher in AB SAT than in FEM SAT. CONCLUSIONS: Results showed that T-cell populations vary by SAT region in females but not males. Both sexes, however, have proportionately more proinflammatory macrophages in upper-body than in lower-body SAT. It remains to be seen how these unique immune cell profiles in males and females with obesity contribute to adipose tissue inflammation and metabolic disease risk.

Differential mutation spectrum and immune landscape in African Americans versus Whites: A possible determinant to health disparity in head and neck cancer.

African Americans (AA) with Head and Neck Squamous Cell Carcinoma (HNSCC) have a worse disease prognosis than White patients despite adjusting for socio-economic factors, suggesting the potential biological contribution. Therefore, we investigated the genomic and immunological components that drive the differential tumor biology among race. We utilized the cancer genome atlas and cancer digital archive of HNSCC patients (1992-2013) for our study. We found that AA patients with HNSCC had a higher frequency of mutation compared to Whites in the key driver genes-P53, FAT1, CASP8 and HRAS. AA tumors also exhibited lower intratumoral infiltration of effector immune cells (CD8+, γδT, resting memory CD4+ and activated memory CD4+ T cells) with shorter survival than Whites. Unsupervised hierarchical clustering of differentially expressed genes demonstrated distinct gene clusters between AA and White patients with unique signaling pathway enrichments. Connectivity map analysis identified drugs (Neratinib and Selumetinib) that target aberrant PI3K/RAS/MEK signaling and may reduce racial disparity in therapy response.

MUCIN-4 (MUC4) is a novel tumor antigen in pancreatic cancer immunotherapy.

Pancreatic cancer (PC) is a highly lethal malignancy with a dismal five-year survival rate. This is due to its asymptomatic nature, lack of reliable biomarkers, poor resectability, early metastasis, and high recurrence rate. Limited efficacies of current treatment modalities treatment-associated toxicity underscore the need for the development of immunotherapy-based approaches. For non-resectable, locally advanced metastatic PC, immunotherapy-based approaches including vaccines, antibody-targeted, immune checkpoint inhibition, CAR-T-cells, and adoptive T-cell transfer could be valuable additions to existing treatment modalities. Thus far, the vaccine candidates in PC have demonstrated modest immunological responses in different treatment modalities. The identification of tumor-associated antigens (TAA) and their successful implication in PC treatment is still a challenge. MUC4, a high molecular weight glycoprotein that functionally contributes to PC pathogenesis, is an attractive TAA. It is not detected in the normal pancreas; however, it is overexpressed in mouse and human pancreatic tumors. The recombinant MUC4 domain, as well as predicted immunogenic T-cell epitopes, elicited cellular and humoral anti-MUC4 response, suggesting its ulility as a vaccine candidate for PC therapy. Existence of PC-associated MUC4 splice variants, autoantibodies against overexpressed and aberrantly glycosylated MUC4 and presence of T-cell clones against the mutations present in MUC4 further reinforce its significance as a tumor antigen for vaccine development. Herein, we review the significance of MUC4 as a tumor antigen in PC immunotherapy and discuss both, the development and challenges associated with MUC4 based immunotherapy. Lastly, we will present our perspective on MUC4 antigenicity for the future development of MUC4-based PC immunotherapy.

Effects of weight loss via high fat vs. low fat alternate day fasting diets on free fatty acid profiles.

Cardiovascular disease risk is associated with excess body weight and elevated plasma free fatty acid (FFA) concentrations. This study examines how an alternate-day fasting (ADF) diet high (HF) or low (LF) in fat affects plasma FFA profiles in the context of weight loss, and changes in body composition and lipid profiles. After a 2-week weight maintenance period, 29 women (BMI 30-39.9 kg/m(2)) 25-65 years old were randomized to an 8-week ADF-HF (45% fat) diet or an ADF-LF (25% fat) diet with 25% energy intake on fast days and ad libitum intake on feed days. Body weight, BMI and waist circumference were assessed weekly and body composition was measured using dual x-ray absorptiometry (DXA). Total and individual FFA and plasma lipid concentrations were measured before and after weight loss. Body weight, BMI, fat mass, total cholesterol, LDL-C and triglyceride concentrations decreased (P < 0.05) in both groups. Total FFA concentrations also decreased (P < 0.001). In the ADF-LF group, decreases were found in several more FFAs than in the ADF-HF group. In the ADF-HF group, FFA concentrations were positively correlated with waist circumference. Depending on the macronutrient composition of a diet, weight loss with an ADF diet decreases FFA concentrations through potentially different mechanisms.